As you read this, I am at the beautiful California Academy of Sciences, announcing the launch of the newest version of Google Earth. This launch is particularly special to me because it marks the moment when Google Earth becomes much more complete — it now has an ocean.

Didn't Google Earth always have an ocean? Technically, yes, well, sort of. We have always had a big blue expanse and some low-resolution shading to suggest depth. But starting today we have a much more detailed bathymetric map (the ocean floor), so you can actually drop below the surface and explore the nooks and crannies of the seafloor in 3D. While you're there you can explore thousands of data points including videos and images of ocean life, details on the best surf spots, logs of real ocean expeditions, and much more.

We were joined at the Academy by many of the dozens of ocean scientists and advocates who helped make this project a reality: friends from National Geographic, the Monterey Bay Aquarium, the National Oceanic and Atmospheric Association, the US Navy, Scripps Oceanography, and Woods Hole Oceanographic Institution, to name just a few. Above all, I would like to acknowledge the work of Dr. Sylvia Earle, who cornered me at a conference three years ago and told me that Google Earth was great but that it wasn't finished (you can read more about that encounter on the Lat Long blog). As much as I hated to admit it, she was right. We on the Google Earth team had been working hard to build a rich 3D map of the world, but we had largely ignored the oceans — two thirds of the planet. Inspired by Sylvia, the team got to work. I hope you are as excited as I am to explore our new Ocean and all of the fascinating stories and images our partners have contributed.

But that's not all we launched today. In addition to Ocean, we introduced new features that we hope will enhance the way people interact with Google Earth and use it to communicate with the world.

Historical Imagery: Until today, Google Earth displayed only one image of a given place at a given time. With this new feature, you can now move back and forth in time to reveal imagery from years and even decades past, revealing changes over time. Try flying south of San Francisco in Google Earth and turning on the new time slider (click the "clock" icon in the toolbar) to witness the transformation of Silicon Valley from a farming community to the tech capital of the world over the past 50 years or so.

Touring: One of the key challenges we have faced in developing Google Earth has been making it easier for people to tell stories. People have created wonderful layers to share with the world, but they have often asked for a way to guide others through them. The Touring feature makes it simple to create an easily sharable, narrated, fly-through tour just by clicking the record button and navigating through your tour destinations.

3D Mars: This is the latest stop in our virtual tour of the galaxies, made possible by a collaboration with NASA. By selecting "Mars" from the toolbar in Google Earth, you can access a 3D map of the Red Planet featuring the latest high-resolution imagery, 3D terrain, and annotations showing landing sites and lots of other interesting features.

For those of you who keep track of version numbers, this is Google Earth 5.0. We felt the addition of the ocean and "time" merited a major bump from 4.3 to 5.0 :-)

Members of the Google Earth team will be publishing in-depth posts about all of the new features in Google Earth 5.0 on the Lat Long blog all week, so be sure to check back there often. And check out our video tour below.